Everything You Know About Obesity Is Wrong

Lesley Williams, a family medicine doctor in Phoenix, tells me she gets an alert from her electronic health records software every time she’s about to see a patient who is above the “overweight” threshold. The reason for this is that physicians are often required, in writing, to prove to hospital administrators and insurance providers that they have brought up their patient’s weight and formulated a plan to bring it down—regardless of whether that patient came in with arthritis or a broken arm or a bad sunburn. Failing to do that could result in poor performance reviews, low ratings from insurance companies or being denied reimbursement if they refer patients to specialized care.

…Diets do not work. Not just paleo or Atkins or Weight Watchers or Goop, but all diets. Since 1959, research has shown that 95 to 98 percent of attempts to lose weight fail and that two-thirds of dieters gain back more than they lost. The reasons are biological and irreversible. As early as 1969, research showed that losing just 3 percent of your body weight resulted in a 17 percent slowdown in your metabolism—a body-wide starvation response that blasts you with hunger hormones and drops your internal temperature until you rise back to your highest weight.

…Yes, nearly every population-level study finds that fat people have worse cardiovascular health than thin people. But individuals are not averages: Studies have found that anywhere from one-third to three-quarters of people classified as obese are metabolically healthy. They show no signs of elevated blood pressure, insulin resistance or high cholesterol. Meanwhile, about a quarter of non-overweight people are what epidemiologists call “the lean unhealthy.” A 2016 study that followed participants for an average of 19 years found that unfit skinny people were twice as likely to get diabetes as fit fat people. Habits, no matter your size, are what really matter. Dozens of indicators, from vegetable consumption to regular exercise to grip strength, provide a better snapshot of someone’s health than looking at her from across a room.

..And, in a cruel twist, one effect of weight bias is that it actually makes you eat more. The stress hormone cortisol—the one evolution designed to kick in when you’re being chased by a tiger or, it turns out, rejected for your looks—increases appetite, reduces the will to exercise and even improves the taste of food.

…Diet is the leading cause of death in the United States, responsible for more than five times the fatalities of gun violence and car accidents combined. But it’s not how much we’re eating—Americans actually consume fewer calories now than we did in 2003. It’s what we’re eating.

For more than a decade now, researchers have found that the quality of our food affects disease risk independently of its effect on weight. Fructose, for example, appears to damage insulin sensitivity and liver function more than other sweeteners with the same number of calories. People who eat nuts four times a week have 12 percent lower diabetes incidence and a 13 percent lower mortality rate regardless of their weight. All of our biological systems for regulating energy, hunger and satiety get thrown off by eating foods that are high in sugar, low in fiber and injected with additives. And which now, shockingly, make up 60 percent of the calories we eat.